U.S. patent number 4,192,466 [Application Number 05/879,457] was granted by the patent office on 1980-03-11 for swirl injection valve.
This patent grant is currently assigned to Kabushiki Kaisha Toyota Chuo Kenkyusho. Invention is credited to Norio Muto, Akinori Saito, Yasusi Tanasawa.
United States Patent |
4,192,466 |
Tanasawa , et al. |
March 11, 1980 |
Swirl injection valve
Abstract
A swirl injection valve for injecting pressurized fluid, such as
fuel, into an engine or the like through passages connecting a fuel
source to an injection port and forming a swirl flow in the fluid
prior to injection by introducing the fluid tangentially into a
swirl chamber located adjacent the port.
Inventors: |
Tanasawa; Yasusi (Nagoya,
JP), Muto; Norio (Aichi, JP), Saito;
Akinori (Nagoya, JP) |
Assignee: |
Kabushiki Kaisha Toyota Chuo
Kenkyusho (Nagoya, JP)
|
Family
ID: |
11970651 |
Appl.
No.: |
05/879,457 |
Filed: |
February 21, 1978 |
Foreign Application Priority Data
|
|
|
|
|
Feb 21, 1977 [JP] |
|
|
52-18401 |
|
Current U.S.
Class: |
239/464;
239/533.12; 239/533.3 |
Current CPC
Class: |
F02M
51/0671 (20130101); F02M 61/06 (20130101); F02M
51/08 (20190201); F02M 61/163 (20130101); F02M
69/044 (20130101); F02M 61/162 (20130101); F02B
1/04 (20130101) |
Current International
Class: |
F02M
51/06 (20060101); F02M 61/16 (20060101); F02M
61/00 (20060101); F02M 61/06 (20060101); F02M
69/04 (20060101); F02M 51/08 (20060101); F02B
1/04 (20060101); F02B 1/00 (20060101); B05B
001/30 () |
Field of
Search: |
;239/464,463,468,471,472,491,492,493,533.1,533.12,533.3 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Marbert; James B.
Attorney, Agent or Firm: Berman, Aisenberg & Platt
Claims
What is claimed is:
1. A swirl injection valve comprising
a nozzle body,
an injection port opening at an end of said nozzle body for
injecting pressurized fluid,
at least one pressurized fluid induction passage provided within
said nozzle body, said pressurized fluid induction passage being
connectable to a pressurized fluid supply source,
a valve means having a movable member interposed into said
injection port for controlling the fluid injection by on-off
controlling the fuel supply to said injection port,
a swirl chamber comprising a chamber having circular cross section
formed at a position adjacent to said injection port within said
nozzle body, said swirl chamber being connected to said injection
port, and
two tangential pressurized fluid supply passages formed within said
nozzle body, which respectively open into a side wall of said swirl
chamber in the tangential direction thereof at symetrically
opposite portions with respect to the axis of said swirl chamber in
order to form a swirl flow of said pressurized fluid within said
swirl chamber,
each of said two tangential pressurized supply passages being
connected to the respective one of said pressurized fluid induction
passages within said nozzle body at a pre-determined angle, and
being formed by a hole penetrating from an outer side wall to an
inner side wall forming said swirl chamber, and a plug member being
inserted into said hole from said outer side wall to said
connecting part of said hole and said passage,
said injection port, pressurized fluid induction passages, swirl
chamber and tangential pressurized fluid supply passages being
formed within said one nozzle body,
whereby the swirl flow of said pressurized fluid may be injected in
a pre-determined timing determined by said valve means.
2. A swirl injection valve according to claim 1, wherein
said movable member is spring biased and is intermittently movable
by the fluid pressure of the intermittently supplied fluid.
3. A swirl injection valve according to claim 1, wherein
said valve means includes a plunger connected to said movable
member located at a predetermined position relative to said
pressurized fluid induction passage and said tangential pressurized
fluid supply passage,
thereby controlling the fuel supply to said injection port by the
intermittent movement of said plunger.
4. A swirl injection valve according to claim 1, wherein
said valve means includes a chamber interposed in said pressurized
fluid induction passage, said movable member being positioned
within said chamber in order to control the opening or closing of
the communication between said chamber and pressurized fluid
induction passage by the axial movement of said movable member.
5. A swirl injection valve according to claim 1, wherein
said valve means comprises an opening of said tangential
pressurized fluid supply passage in said swirl chamber and said
movable member interposed in said swirl chamber and pressurized by
a spring means,
thereby controlling the opening or closing of the communication
between tangential pressurized fluid supply passage and said swirl
chamber by the axial movement of said movable member.
6. A swirl injection valve according to claim 1, wherein
said swirl chamber is formed by an inner side wall of a hollow tip
portion of said nozzle body and an outer side wall of a
truncated-cone tip portion of said movable member.
7. A swirl injection valve according to claim 1, wherein
said swirl chamber is formed by an inner side wall of a hollow tip
portion of said nozzle body and outer side wall of a narrow stepped
cylindrical tip portion of said movable member, the diameter of
said inner side wall of said tip portion of said nozzle body being
larger than that of said outer side wall of said tip portion of
said movable member.
8. A swirl injection valve according to claim 1, wherein
said swirl chamber comprises a cylindrical chamber provided at a
tip portion of said nozzle body, and
said injection port is coaxially formed at a bottom surface of said
cylindrical chamber.
9. A swirl injection valve according to claim 1, wherein
said nozzle body comprises a main body of a hollow member having a
bottomed portion and a threaded part at a lower outer side wall
thereof, an annular member, a stepped hollow member having a bottom
portion, and a hollow adapter member having two threaded parts
respectively at upper inner side wall and lower outer side wall
thereof and stepped inner wall,
said injection port comprises a small hole having a predetermined
diameter coaxially provided at said bottom portion of said stepped
hollow member of said nozzle body,
said pressurized fluid induction passage comprises a passage
axially formed in a side wall of said main body, a first circular
groove coaxially formed at a top surface of said annular member,
two passages connecting to said circular groove coaxially formed in
a side wall of said annular member, a second circular groove
coaxially formed at a top surface of said stepped hollow member and
connected to said two passages of said annular member, and two
passages axially formed in a side wall of said stepped hollow
member and connected to said second circular groove,
said valve means comprises said movable member comprising a needle
valve having a conical top portion inserted within an inner side
wall of said stepped hollow member, a conical push rod inserted
within an inner portion defined by side walls of said main body and
annular member and connected to said needle valve, and a coil
spring for pressing said push rod inserted within an inner portion
defined by side wall and a wall of said bottom portion of said main
body,
said swirl chamber is formed by said conical top portion of said
needle valve and a tapered bottom surface of said bottom portion of
said stepped hollow member,
each of said two tangential pressurized fluid supply passages is
connected to the respective one of said two passages at a right
angle and is formed by a hole penetrating from an outer side wall
to an inner side wall forming said swirl chamber of said stepped
hollow member and a plug member inserted into said hole from said
outer side wall to said connecting part of said hole and said
passage, said two tangential pressurized fluid supply passages
being provided in the plane perpendicular to the axis of said swirl
chamber.
10. A swirl injection valve according to claim 9, wherein
said nozzle body is provided at an auxiliary combustion chamber
having a glow plug connected to said main combustion chamber of a
diesel engine, and said swirl chamber has relations of
di/de.ltoreq.2 and h/de.ltoreq.0.5 wherein di is the diameter of
the swirl chamber, h is the height of the swirl chamber and de is
the diameter of the injection port.
11. A swirl injection valve according to claim 1, wherein
said nozzle body comprises a main body of a hollow member which
comprises two parts having two different diameters, a hollow plug
member having electric and fluid connectors equipped in a top
portion of said main body, a hollow intermediate member having a
cross shaped longitudinal section interposed within an inner wall
of said large diameter part of said main body, an annular member
inserted in the annular part of said main body, a stepped hollow
member having 0 ring and a bottom portion fixedly inserted within a
lower inner wall of said smaller part of said main body,
said injection port comprises a small hole having a predetermined
diameter coaxially provided at said bottom portion of said stepped
hollow member of said nozzle body,
said pressurized fluid induction passage comprises a tube inserted
within an inner wall of said intermediate member and connected to
said fluid connectors of said plug member of said nozzle body, a
tube inserted within a stepped inner wall of said annular member,
and embedded into a top portion of said stepped hollow member, said
tube within said annular member having a plurality of holes at
lower portions thereof and two passages axially provided at a side
wall of said stepped hollow member and connected to said holes of
said tube within said annular member,
said valve means comprises said movable member comprising a needle
valve having a tip portion of reduced diameter inserted within said
inner wall of said stepped hollow member and injecting port and
projected from an outer bottom surface of said injecting port, said
hollow plunger connected to said needle valve by said tube having
holes, coil means for pressing said hollow plunger inserted within
said stepped inner wall of said intermediate member, and magnetic
coil connected to said electric connector of said plug member
fixedly inserted between an inner wall of said large part of said
main body and lower outer wall of said intermediate member,
said swirl chamber is formed by said stepped outer wall having a
small diameter of said needle valve and an enlarged inner circular
wall having large diameter of said stepped hollow member,
each of said two tangential pressurized fluid supply passages is
connected with the respective one of said two passages at a right
angle and is formed by a hole penetrating from an outer side wall
to said inner enlarged side wall of said stepped hollow member and
a plug member inserted into said hole from said outer side wall to
said connecting part of said hole to end said passage, said two
tangential pressurized fluid supply passages provided in the plane
perpendicular to the axis of said swirl chamber.
12. A swirl injection valve according to claim 11, wherein
said nozzle body is provided at a side wall of an intake pipe
adjacent to an intake valve in gasoline engine, and said swirl
chamber has relations of di/de.ltoreq.2 and h/de.ltoreq.0.5 wherein
di is the diameter of the swirl chamber, h is the height of the
swirl chamber and de is the diameter of the injection port.
13. A swirl injection valve according to claim 1, wherein
said nozzle body comprises a main body of a hollow member which
comprises two parts having two different diameters, a hollow plug
member having an electric and fluid connectors equipped in a top
portion of said main body, a hollow intermediate member having a
cross shaped longitudinal section interposed within an inner wall
of said large diameter part of said main body,
an annular member equipped in the smaller part of said main body, a
stepped hollow member having O ring and a bottom portion fixedly
inserted within a lower inner wall of said smaller part of said
main body,
said pressurized fluid induction passage comprises a tube inserted
within an inner wall of said intermediate member and connected to
said fluid connectors of said plug member of said nozzle body, a
tube inserted within a stepped inner wall of said annular member,
and embedded into a top portion of said stepped hollow member, said
tube within said annular member having a plurality of holes at
lower portions thereof and two passages axially provided at a side
wall of said stepped hollow member and connected to said holes of
said tube within said annular member,
said valve means comprises said movable member comprising a needle
valve having a conical top portion inserted within an inner side
wall of said stepped hollow member, said hollow plunger connected
to said needle valve by said tube having holes, coil means for
pressing said hollow plunger inserted within said stepped inner
wall of said intermediate member, and magnetic coil connected to
said electric connector of said plug member fixedly inserted
between an inner wall of said large part of said main body and a
lower outer wall of said intermediate member,
said swirl chamber is formed by said conical top portion of said
needle valve and a tapered bottom surface of said bottom portion of
said stepped hollow member,
each of said two tangential pressurized fluid supply passages if
connected to the respective one of said two passages at a right
angle and is formed by a hole penetrating from an outer side wall
to an inner side wall forming said swirl chamber of said stepped
hollow member and a plug member inserted into said hole from said
outer side wall to said connecting part of said hole to end said
passage, said two tangential pressurized fluid supply passages
provided in the plane perpendicular to the axis of said swirl
chamber.
14. A swirl injection valve according to claim 13, wherein
said nozzle body is provided at the top wall of a surging tank
interposed in the intake pipe of a gasoline engine,
thereby controlling the fuel injection in response to the
electrical signal from the thermo-time switch at the start time of
said engine, and said swirl chamber has relations of di/de.ltoreq.2
and h/de.ltoreq.0.5 wherein di is the diameter of the swirl
chamber, h is the height of the swirl chamber and de is the
diameter of the injection port.
15. A swirl injection valve according to claim 1, wherein
said nozzle body comprises a main body composed of a hollow member
and a bottom portion, said hollow member having a threaded part at
the lower outer side wall thereof, an annular member, a bottomed
hollow member having a bottom portion which has a conical groove
coaxially formed in an inner bottom surface thereof and stepped
inner side wall and a threaded part at outer side wall thereof and
an adapter member composed of a hollow member and a bottom portion,
said hollow member having two threaded parts respectively at upper
inner side wall and lower inner side wall thereof and said bottom
portion having a small through hole having a predetermined diameter
coaxially to form said injection port,
said pressurized fluid supply passage comprises a passage axially
formed in a side wall of said main body, a first circular groove
coaxially formed at a top surface of said annular member, a passage
connected to said first circular groove coaxially formed in a side
wall of said annular member, a second circular groove formed at a
top surface of said bottomed hollow member and connected to said
passage of said annular member, a passage formed in a side wall of
said bottomed hollow member and connected to said second circular
groove, and two passages axially and symmetrically formed in said
bottom portion of said bottomed hollow member and connected to said
passage formed in a side wall thereof,
said valve means comprises said movable member comprising a needle
valve having a stepped conical top portion inserted within an inner
side wall of said bottomed hollow member and received by said
conical groove of said bottom portion of said bottomed hollow
member, a conical push rod inserted within an inner portion defined
by side walls of said main body and annular member and connected to
said needle valve, a coil spring for pressing said push rod
inserted within an inner portion defined by side wall and a wall of
said bottom portion of said main body, and a cylindrical hollow
chamber defined by a reduced portion of said stepped inner side
wall of said bottomed hollow member and said bottom portion thereof
and inserted between said passage and said two passages of said
bottomed hollow member,
said swirl chamber comprises a cylindrical chamber having a
predetermined diameter and height, which is formed within said
bottom portion of said bottomed hollow member coaxially and at a
position below said conical groove of said bottomed hollow
member,
each of said two tangential pressurized fluid supply passages is
connected to the respective one of said two passages of said
bottomed hollow member at a right angle and is formed by a hole
penetrating from an outer side wall to an inner side wall forming
said swirl chamber of said stepped hollow member and a plug member
inserted into said hole from said outer side wall to said
connecting part of said hole and each of said two passages, said
two tangential pressurized fluid supply passages being provided in
the plane perpendicular to the axis of said swirl chamber.
16. A swirl injection valve according to claim 15, wherein
said nozzle body is provided at an auxiliary combustion chamber
having a spark plug connected to said main combustion chamber in a
gasoline engine, and said swirl chamber has relations of
di/de.ltoreq.2 and h/de.ltoreq.0.5 wherein di is the diameter of
the swirl chamber, h is the height of the swirl chamber and de is
the diameter of the injection port.
17. A swirl injection valve according to claim 1, wherein
said nozzle body comprises a main body composed of a hollow member
having a bottom portion and a threaded part at a lower outer side
wall thereof, an annular member, a stepped hollow member having a
bottom portion and a hollow adapter member which has two threaded
parts at the upper inner side wall and the lower outer side wall
thereof respectively and stepped inner wall thereof,
said injection port comprises a small hole having a predetermined
diameter coaxially provided at said bottom portion of said stepped
hollow member of said nozzle body,
said pressurized fluid induction passage comprises a passage
axially formed in a side wall of said main body, a first circular
groove coaxially formed at a top surface of said annular member,
two passages connected to said circular groove coaxially formed in
a side wall of said annular member, a second circular groove
coaxially formed at a top surface of said stepped hollow member and
connected to said two passages of said annular member, and two
passages axially formed in a side wall of said stepped hollow
member and connected to said second circular groove,
said valve means comprises said movable member comprising a needle
valve having a conical top portion inserted within an inner side
wall of said stepped hollow member, a conical push rod inserted
within an inner portion defined by side walls of said main body and
annular member and connected to said needle valve, and a coil
spring for pressing said push rod inserted within an inner portion
defined by side wall and a wall of said bottom portion of said main
body,
said swirl chamber is formed by said conical top portion of said
needle valve and a tapered bottom surface of said bottom portion of
said stepped hollow member, so that said chamber is completely
occupied by said needle valve when said needle valve is seated on
said tapered bottom surface of said stepped hollow member,
each of said two tangential pressurized fluid supply passages is
connected to the respective one of said two passages at a right
angle and formed by a hole penetrating from an outer side wall to
an inner side wall forming said swirl chamber of said stepped
hollow member and a plug member inserted into said hole from said
outer side wall to said connecting part of said hole and each of
said passages, said two tangential pressurized fluid supply
passages being provided in the plane perpendicular to the axis of
said swirl chamber.
18. A swirl injection valve according to claim 1, wherein
said nozzle body comprises a main body composed of a hollow member
having a bottomed portion and a threaded part at a lower outer side
wall thereof, an annular member, a stepped hollow member having a
bottom portion and a hollow adapter member which has two threaded
parts at upper inner side wall and lower outer side wall thereof
respectively and stepped inner wall,
said injection part comprises a small hole having a predetermined
diameter coaxially provided at said bottom portion of said stepped
hollow member of said nozzle body,
said pressurized fluid induction passage comprises a passage
axially formed in a side wall of said main body, a first circular
groove coaxially formed at a top surface of said annular member,
two passages connecting to said circular groove coaxially formed in
a side wall of said annular member, a second circular groove
coaxially formed at a top surface of said stepped hollow member and
connected to said two passages of said annular member, and two
passages axially formed in a side wall of said stepped hollow
member and connected to said second circular groove,
said valve means comprises said movable member comprising a needle
valve having a conical top portion inserted within an inner side
wall of said stepped hollow member, a conical push rod inserted
within an inner portion defined by side walls of said main body and
annular member and connected to said needle valve, and a coil
spring for pressing said push rod inserted within an inner portion
defined by said wall and a wall of said bottom portion of said main
body,
said swirl chamber is coaxially formed within the nozzle body by an
outer wall of said conical top portion of said needle valve and an
enlarged inner circular wall having a large diameter of said
stepped hollow member and located above said conical top portion of
said needle valve,
each of said two tangential pressurized fluid supply passages is
connected to the respective one of said passages at an angle larger
than a right angle and formed by a hole penetrated from an outer
side wall to an inner side wall forming said swirl chamber of said
stepped hollow member and a plug member inserted into said hole
from said outer side wall to said connecting part of said hole and
each of said passages, said two tangential pressurized fluid supply
passages being provided with the axis of its opening inclined with
respect to the axis of said swirl chamber.
19. A swirl injection valve comprising
a nozzle body,
an injection port on said nozzle body,
valve means for opening and closing said port,
first fluid passage means within said body communicable with a
fluid supply source,
a swirl chamber having a circular cross section located adjacent
said port and communicable therewith, and
second fluid passage means connecting said first passage means and
said chamber, and opening tangentially into said chamber, said
injection port, first fluid passage means, swirl chamber and second
fluid passage means being formed within said one nozzle body,
whereby a swirl flow may be imparted to a fluid within said
chamber.
20. A swirl injection valve according to claim 19, wherein
said second fluid passage means comprises at least one passage
extending transversely of said nozzle body.
21. A swirl injection valve according to claim 19, wherein
said second fluid passage means comprises two passages extending
transversely of said nozzle body and opening tangentially into said
swirl chamber at symmetrically opposite positions with respect to
the axis of said chamber.
22. A swirl injection valve according to claim 20, wherein
said passage is formed by a bore extending from the outer surface
of said nozzle body to said chamber.
23. A swirl injection valve according to claim 20, wherein
said chamber is substantially cylindrical in shape, and said
passage extends substantially perpendicularly to the axis of said
chamber.
Description
SUMMARY OF THE INVENTION
This invention relates to a swirl injection valve useful as a
liquid particle generator, for example, as an injection valve for
various combustion apparatus or as a fuel injection valve for
diversified types of thermal engines.
Various types of fuel injection valves have been used widely in
diesel and gasoline engines. However, the conventional fuel
injection valves invariably have inferior atomization
characteristics due to drawbacks in their construction or accuracy,
are greatly influenced by the injection pressure, and have low
response of fuel injection to the injection pressure. In addition,
the conventional injection valves practically have problems in that
they have complicated construction which involve various troubles
and require high precision, thereby making the manufacturing,
machining and assembling processes extremely difficult. Due to
faulty fuel supply, it has been difficult to effect complete
combustion in the above-mentioned engines, resulting in production
of toxic gases such as hydrocarbons HC and carbon monoxide CO in
the exhaust gases to cause air pollution, producing troubles to the
engine operation to lower the efficiency of various operations, and
inviting uneconomical fuel consumption.
In an attempt to eliminate the above-mentioned drawbacks and
difficulties, the present inventors have conducted numerous
experiments and analyses on various types of swirl injection valves
to study their atomization characteristics, namely, the particle
conditions of the sprayed liquid (including numerical particle
distribution, particle size distribution, surface area
distribution, weight and volume distribution, and means diameter of
distributed particles) and to investigate the possibility of
obtaining a swirl injection valve with excellent atomization
characteristics. As a result, the present inventors succeeded in
developing a swirl injection valve which, even at low injection
pressure, can inject a liquid in atomized particles which have been
conventionally difficult to produce, with a high response to the
injection pressure by making the diameter and height of a swirl
chamber of injection valve extremely small, contrary to the common
technical knowledge. Reference is made to Japanese Patent No.
815112. This swirl injection valve has been and is widely used in
various fields of industry, particularly as a fuel injection valve
for combustion apparatus in general and for the combustors for gas
turbines. This valve shows excellent atomization characteristics
and high response to the injection pressure to ensure practically
satisfactory high performance and efficiency when it is used in the
combustion apparatus where the fuel is injected constantly without
variations in relation with time.
However, the above-mentioned swirl injection valve has problems
when applied to reciprocating gasoline or diesel engines where the
fuel is supplied at an inconstant flow rate varying with time or
the fuel is injected intermittently. More particularly, the swirl
injection valve of our prior invention is equipped with a valve
device which communicates with the swirl chamber and continuously
performs the opening and closing operations of an injection valve
at an extremely high speed. However, such a valve device has
problems inherent in its construction or in the precision needed in
machining and assembling. Coupled with such technical limitations
are the unsatisfactory or in some cases deteriorated atomization
characteristics and response to the injection pressure, which
invite various difficulties such as directional instability of the
injected fuel and the like. Therefore, the above-mentioned
injection valve causes inconvenience of engine operations such as
misfiring due to incomplete combustion of the fuel caused by faulty
fuel supply, production of toxic gases, and uneconomical
consumption of the fuel.
The present invention forms a strong and fast swirl flow within the
swirl chamber by tangentially supplying the pressurized fluid
having no velocity component of an axial direction into the swirl
chamber, so that the atomization characteristics and response to
the injection pressure are improved. Further, by this invention
there is provided a practically useful swirl injection valve which
has improved and simplified construction to allow facilitated
manufacturing, machining and assembling suitable for mass
production, which is excellent in durability and easy to handle,
and which has optimum atomization characteristics and quick
response of the atomization to the injection pressure.
It is one object of the present invention to provide a novel and
practically useful swirl injection valve which is excellent in
durability and easy to handle.
It is another object of the present invention to provide a swirl
injection valve which forms a strong and fast swirl flow within the
swirl chamber by tangentially supplying the pressurized fluid
having no velocity component of the axial direction therein.
It is still another object of the present invention to provide a
swirl injection valve which even at a low injection pressure
injects a fuel with excellent atomization characteristics and high
response to the injection pressure without dribbling, forming of
coarse particles of fuel, or other defects and drawbacks of the
conventional valves.
It is still another object of the present invention to provide a
swirl injection valve used as a fuel injection valve for combustion
apparatus or thermal engines, by which generation of toxic gases
causing air pollution is prevented, and the stabilized and
smoothened operation of apparatus or engines is achieved
efficiently at a low fuel cost.
It is still another object of the present invention to provide a
swirl injection valve having an improved and simplified
construction to allow facilitated manufacturing, machining and
assembling suitable for mass production.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view showing a swirl injection
valve constituting the first embodiment of the invention;
FIG. 2 is an enlarged sectional view of the nozzle member of FIG.
1;
FIG. 3 is a transverse sectional view of the invention shown in
FIG. 1;
FIG. 4 is a sectional view, with parts broken away, showing the
swirl injection valve of the first embodiment as applied to a
diesel engine;
FIGS. 5 to 8 are views showing the conditions of sprays produced by
the swirl injection valve of the first embodiment in relation with
injection pressure;
FIGS. 9 and 13 are sectional views showing various conventional
injection valves;
FIGS. 10 to 12 are views showing the conditions of sprays produced
by the conventional injection valve of FIG. 9;
FIG. 14 is a view showing the condition of the spray produced by
the conventional injection valve of FIG. 13;
FIG. 15 is a longitudinal sectional view showing a swirl injection
valve constituting the second embodiment of the invention;
FIG. 16 is an enlarged sectional view of the end portion of the
embodiment shown in FIG. 15.
FIG. 17 is a sectional view showing the swirl injection valve of
the second embodiment as applied to a gasoline engine;
FIGS. 18 to 20 are views showing the conditions of sprays produced
by the swirl injection valve of the second embodiment in relation
with the injection pressure;
FIGS. 21 to 23 are views showing the conditions of sprays produced
by a conventional electromagnetic injection valve;
FIG. 24 is a longitudinal sectional view showing a swirl injection
valve constituting the third embodiment of the present
invention;
FIG. 25 is a transverse sectional view of the embodiment shown in
FIG. 24;
FIG. 26 is a section view showing the swirl injection valve of the
third embodiment applied as a cold start injector;
FIG. 27 is a view showing the condition of spray produced by a cold
start injector using the conventional swirl injection valve;
FIGS. 28 and 29 are views showing the conditions of sprays produced
by the swirl injection valve of the third embodiment in relation
with the injection pressure;
FIG. 30 is a partially cut-away sectional view showing a swirl
injection valve constituting the fourth embodiment of the present
invention;
FIGS. 31 and 32 are sectional views showing the swirl injection
valve of the fourth embodiment as applied to a pre-chamber type
gasoline engine; and
FIGS. 33 and 34 are partially cut-away longitudinal sectional views
showing further embodiments of the present invention.
In the figures: 1 ... denotes a nozzle body; 2 ... an injection
port; 3 ... a valve seat; 4 ... a nozzle member; 5 ... a needle
valve guide bore; 6 ... a needle valve; 8 ... a swirl chamber; 40
... a tangential pressurized fuel supply passage; 9 ... a valve
device.
DETAILED DESCRIPTION OF THE INVENTION
Hereafter, the construction, operation and effects of the swirl
injection valve according to the present invention are described in
detail by way of preferred embodiments.
Referring to FIGS. 1 to 3, there is shown a fuel injection valve
A.sub.1 which forms the first embodiment of the present invention
and is of the fuel pressure operated type in which a needle valve
is seated and unseated by fuel pressure and valve spring pressure
to open and close a fuel induction passage and wherein the initial
fuel injection pressure is adjusted by changing the thickness of a
flat plate-like washer. The fuel injection valve A.sub.1 has, at
the fore end of a nozzle body 1, a nozzle member 4 which has a fuel
injection port 2 and a conical valve seat 3 located inwardly of an
communicating with the fuel injection port 2. The nozzle body 1 and
the nozzle member 4 are centrally provided with a guide bore 13 and
a needle valve guide bore 5 for slidably receiving a push rod 14
and a needle valve 6, respectively, through precision fitting.
Within the nozzle member 4, the needle valve 6 has its fore end
formed in a conical shape for airtight abutting engagement with the
valve seat 3; to form a conical pressure receiving surface 16. When
a jet of fuel is supplied intermittently, the fuel pressure acts
against the pressure of a valve spring 60 of the needle valve 6 to
open the passage between the valve seat 3 and needle valve 6, as
will be described hereinafter. The nozzle member 4 is provided with
a swirl chamber 8 which consists of a combination of concentric
hollow truncated-cone and cylindrical sections, between the valve
seat 3 and a conical pressure receiving surface 61 of the needle
valve 6. The swirl chamber 8 has, in the first embodiment, a
diameter di.ltoreq.4mm and a height h.ltoreq.1mm.
These values are given only by way of example and the first
embodiment is not limited to them in any way whatsoever. More
particularly, the present inventors have already found that the
most efficient swirl injection valve has an injection port and a
swirl chamber which respectively satisfy
where di is the diameter of the swirl chamber, h is the height of
the swirl chamber and de is the diameter of the injection port;
thereby resulting in a swirl injection valve which has optimum
atomizing characteristics, which produces sprays of fine particles
that have thus far been difficult to obtain at low injection
pressures, which is very effective in accelerating the atomization,
and which has a quick response to the injection pressure.
Therefore, the dimensions of the respective parts should be
determined by selecting values which satisfy the above-mentioned
relations.
As shown in FIG. 3, the swirl chamber 8 communicates with
tangential pressurized fuel supply passages 40 bored through the
outer peripheral wall of the nozzle member 4 in a direction
tangential to the inner periphery of the swirl chamber 8. The
tangential pressurized fuel supply passages 40 have the axes of the
respective outlets in a direction tangential to the inner
peripheral 80 of the swirl chamber 8 and are designed to impart
swirling movement about the axis of the swirl chamber to the
pressurized fuel to be supplied thereto, with no velocity component
of an axial direction, the outlets each being opened into the swirl
chamber in the same direction as the swirling movement of the
pressurized fuel or fluid. The nozzle member 4 and the nozzle body
1 have, in the respective side walls 41 and 11, a plurality of
pressurized fuel induction passages 42 and 12 which are
communicable with each other through an annular groove 412 which is
provided between opposing end faces of the nozzle member 4 and the
nozzle body 1. At one end, the pressurized fuel induction passages
42 communicate with the swirl chamber 8 through the tangential
pressurized fuel passages 40 and with the injection port 2 through
the valve device 9. At the other end, the pressurized fuel
induction passages 12 communicate with a fuel source (not shown)
through a fuel pump (not shown). The nozzle member 4 has plug
members 43 secured integrally and in an airtight fashion into open
bore portions on the outer side of the junctions of the tangential
pressurized fuel supply passages 40 and the pressurized fuel
induction passages 42, thereby plugging the unnecessary bore
portions on the outer side of the aforementioned junctions. The
nozzle body 1 has the nozzle member 4 secured to its fore end
coaxially and integrally by threading a cap nut 44 on the threaded
portion 45. The rear end of the needle valve 6 is in abutting
relation with the push rod 14 which is mounted coaxially therewith
and slidably received in the guide bore 13 in the nozzle body 1.
The push rod 14 is provided with a spring seat 62 for one end of a
valve spring 60 which urges the needle valve 6 toward the valve
seat 3. The other end of the valve spring 60 is abutted through a
washer 63 against the end of a closed bore 16 which is formed
centrally of the nozzle body 1. Thus, a needle valve pressing
mechanism 64 is constituted by the needle valve 6, push rod 14,
valve spring 60 and washer 63. The pressing force of the needle
valve pressing mechanism 64, which urges the needle valve 6 toward
the valve seat, can be adjusted by replacing the washer 63 by
another washer of different thickness. The just-mentioned pressing
force opposes the fuel pressure which acts on the conical pressure
receiving surface 61 of the needle valve 6.
FIG. 4 shows the swirl injection valve A.sub.1 of the first
embodiment as applied to a diesel engine (compression ignition).
The diesel engine 100 is provided with a cylinder 102 in a cylinder
block 101 and a reciprocable piston 103 connected to a crank shaft
by a connecting rod (both not shown). In a cylinder head 104, there
are provided an intake port 106 which communicates with an intake
passage 105, and an exhaust port which communicates with an exhaust
passage (both not shown). Both ports are in communication with an
exhaust passage (both not shown). Both ports are in communication
with the combustion chamber 108 respectively through an intake
valve 109 and an exhaust valve (not shown) which are controlled to
open and close both ports at predetermined periods in synchronism
with the rotation of the engine. An auxiliary combustion (or
vortex) chamber 111 is provided over the combustion chamber 108 and
communicates with the latter through passage 110. The injection
port 2 of the above-described swirl injection valve A.sub.1 opens
into the bottom of the auxiliary combustion chamber 111 to inject a
predetermined amount of fuel into the auxiliary combustion chamber
111 for predetermined time periods in relation to the operation of
the engine. A starting glow plug 112 is provided in the auxiliary
combustion chamber 111 in a position adjacent to the swirl
injection valve A.sub.1 for initially igniting the sprayed fuel by
electric heat.
The swirl injection valve A.sub.1 of the first embodiment, as
constructed above, operates in the following manner.
During the up stroke of the piston 103, the air supplied to the
combustion chamber 108 through the intake passage 105, intake valve
109 and intake port 106 is compressed to a high degree. In the
meantime, the swirl injection valve A.sub.1 injects the fuel into
the auxiliary combustion chamber 111 with optimum atomization
characteristics and response to injection pressure and, at the time
of engine start, the injected fuel is ignited by the glow plug 112
whereupon the flames propagate into the combustion chamber 108
through the communicating passage 110. During the subsequent
operation of the engine 100, the fuel injected into the auxiliary
chamber 111 by the swirl injection valve A.sub.1 is spontaneously
ignited, and the flames propagate into the highly compressed air in
the combustion chamber 108 through the communicating passage 110
and ignite the compressed air to complete its combustion.
To describe the operation of the swirl injection valve A.sub.1 of
the first embodiment in greater detail, the swirl injection valve
A.sub.1 has the injection port 2 normally closed by the needle
valve 6 due to the pressing force of the needle valve pressing
mechanism 64, as shown in FIG. 1. However, when fuel is supplied to
and enters the swirl chamber 8 in synchronism with the
reciprocating movement of the plunger of the fuel pump to increase
the fuel pressure to a predetermined valve opening valve, the
needle valve 6 is lifted against the pressing force of the
afore-mentioned needle valve pressing mechanism 64 by action of the
entering fuel against surface 61 to open the injection port 2,
whereupon the fuel is permitted to flow from its source through the
pressurized fuel induction passages 12 and 42 and the tangential
pressurized fuel supply passages 40, and tangentially into the
swirl chamber 8 having a small diameter and height. Within the
swirl chamber 8, a strong and fast swirl flow is formed since the
pressurized fluid, having no velocity component of an axial
direction, is tangentially supplied to the swirl chamber. As a
result, the fuel is injected through injection port 2 into the
auxiliary combustion chamber 111 in the form of an atomized spray
with optimum atomization characteristics and high atomization
response to the injection pressure. Upon injecting the fuel through
the injection port 2, a major part of the fuel pressure assumes a
swirling velocity in the tangential direction while the remainder
assumes an axial velocity, and the fuel advances along a straight
line composed of the mean axial flow velocity and mean tangential
velocity. Hence, a hollow liquid film of trumpet or bell shape is
formed as a whole. As the injection pressure increases, the shape
of the liquid film changes from a tulip shape (cone shape) to a
bell shape and then to a trumpet shape with increased atomization.
Since the liquid film becomes very thin when spaced in a trumpet
shape, the peripheral portions of the film break up into a
multitude of fine liquid particles which scatter in atomized
condition.
When the swirl injection valve A.sub.1 of the first embodiment is
applied to the diesel engine 100, for instance, the swirl injection
valve A.sub.1 effects the opening and closing operation
approximately 200-2500 times per minute. The representative shapes
and dimensions of the swirl injection valve A.sub.1 and the sprayed
conditions of the fuel in relation to the various operating
conditions of the diesel engine are as follows.
As for the swirl injection valve, the swirl chamber has a diameter
di.ltoreq.4 mm and a height h.ltoreq.1 mm, the injection port has a
diameter de=1 mm and the tangential pressurized fuel supply passage
has a diameter ds =0.4 mm.
Even at relatively low fuel pressure in the range of 2-5
kg/cm.sup.2, the fuel is sprayed in the form of a trumpet and at a
uniform flow rate as shown in FIG. 5, showing practically optimum
atomization characteristics and producing a spray of fine particles
which has conventionally been difficult to obtain and which is
extremely effective in accelerating the atomization of the fuel,
with a quick response to the injection pressure.
With a diesel engine operating under the conditions where the
rotational speed of the fuel pump is n=750 rpm, the injection valve
opening pressure is Pe=50 kg/cm.sup.2, and the maximum pressure is
Pmax=100-200 kg/cm.sup.2, the spray of fuel from the swirl
injection valve A.sub.1 is immediately spread in the form of a
tulip at the initial time point of injection, as shown in FIG. 6.
The spread liquid film becomes thin and is atomized in the distant
portions from the injection port with relatively high density in
the center portions and relatively low density in the peripheral
portions, to be scattered with optimum atomization characteristics
and quick response to the injection pressure. The spray is
satisfactory practically without any dribbling or forming of coarse
particles of fuel or other defects which are often encountered with
the conventional injections valves.
In a continued injection operation of fuel by the swirl injection
valve A.sub.1, the spray is efficiently spread further from the
tulip shape into a trumpet shaped, very thin liquid film as shown
in FIG. 7 and the spread spray is atomized into extremely fine
particles immediately and uniformly over a large area to be
diffused and mixed with air, efficiently realizing sprays of
atomized fuel particles which could not have been obtained by
conventional injection valves.
Immediately before the completion of fuel injection by the swirl
injection valve A.sub.1, the spray still retains a liquid film of
trumpet shape as shown in FIG. 8, and the peripheral portions of
the injected spray retain a stepped trumpet form maintaining the
uniformly atomized state until the completion of fuel injection
with optimum atomization characteristics. Upon termination, the
spray is immediately and effectively stopped, with the fuel supply
instantly stopped without cut-off defects or after-dribbling of
fuel, which are encountered in conventional fuel injection valves.
Therefore, excellent practical effects can be achieved.
It may be pointed out that the known fuel injection valves on the
market are all complicated in shape and construction, and difficult
to manufacture and assemble. As a representative thereof, FIG. 9
illustrates a nozzle member of a fuel pressure operated type
injection valve B which has a piston nozzle 69. Upon comparing the
fuel sprays produced by the fuel injection valve B and the
above-described fuel injection valve A.sub.1 of the first
embodiment, it will be clear that the latter is far superior to the
former. In FIG. 9, the needle valve 7, fuel chamber 107 and nozzle
member 49 are different from the counterparts in the fuel injection
valve A.sub.1 in shape, construction and the manner in which they
are assembled but like parts are designated by like reference
numerals, omitting their explanations.
Under conditions where the fuel pressure is 5 kg/cm.sup.2, the
rotational speed of the fuel pump is 1000 rpm, the injection valve
opening pressure is Pe=50-70 kg/cm.sup.2 and the maximum pressure
is Pmax=200-500 kg/cm.sup.2, at the initial time point of injection
the fuel injection valve B produces a rod-like liquid film as shown
in FIG. 10, without spreading. Extremely coarse particles and a
film are assembled at a non-uniform flow rate in the distant
portions from the nozzle 69, showing inferior atomization
characteristics, extremely low atomization response to the
injection pressure, and dripping of the fuel.
In continued injection of fuel by the valve B, the fuel appears in
the form of a diverging liquid film of relatively small injection
angle, as shown in FIG. 11. The moment the liquid film spreads, it
becomes thinner with relatively higher density in the center
portion distant from the nozzle 69 and lower density in the
peripheral portions distant from the nozzle 69, forming a spray of
particles having an average diameter greater than 50 .mu.m.
Therefore, excellent atomization characteristics and high response
to the injection pressure cannot be obtained by the fuel injection
valve B.
Immediately before the completion of injection by the valve B, the
fuel is again injected in the form of a rod-like liquid film
forming a continuation of extremely coarse particles in the distant
portions from the nozzle 69 where no atomized particles are
present. Upon termination of injection, the fuel supply cannot be
stopped completely without cut-off failure and after-dribbling of
fuel.
Among the swirl fuel injection valves already developed by the
present inventors, there is a valve C taking the form shown in FIG.
13 (illustrating primarily the nozzle member). The swirl fuel
injection valve C is provided with tangential pressurized fuel
supply passages 417 on the outer peripheral surface 415 of a needle
valve 414 which fits a needle valve guide bore 411 of a nozzle
member 413. The tangential pressurized fuel supply passages 417
extend in a direction tangential to the inner periphery 416 of the
needle valve guide bore 411 and inclined with respect to the axis
of the needle valve 414. A swirl chamber 418 is provided between
the lower end face 419 of the needle valve 414 and the inner wall
surface 420 of the needle valve guide bore 411.
The swirl injection valve C is not suitable for mass production
since it is extremely difficult to manufacture, machine and
assemble the needle valve 414. In particular, the needle valve 414
often becomes defective because the tangential pressurized fuel
supply passages 417 are beyond tolerance and are not acceptable due
to the thermal treatment which is required to impart high abrasive
and heat resistances to the valve. In addition, there are problems
because the tangential passages 417 are deformed due to the wear by
the repeated reciprocating movements of needle valve 414 and the
clearance between the needle valve 414 and the needle valve guide
417 is widened. This causes trouble in injecting the necessary
amount of fuel and requires repair and replacements of parts.
The condition of spray produced by the swirl injection valve C in
continued injection is shown in FIG. 14, from which it will be seen
that the spray lacks directional stability due to defects in
fabrication and machining processes of the injection valve. There
are problems in the atomization characteristics as well as in
response to the injection pressure. More specifically, the spray
injected from the valve C diverges like an unfolded fan with a
greater injection angle as compared with that of the spray produced
by the fuel injection valve B, but its liquid film injection
deviates to one side of the axis of the injection port and becomes
thinner toward the diverged portions. The spray has good
atomization characteristics even in the distant portions, but the
direction of injection is greatly deviated to one side with
non-uniform spray distribution, so that it has a tendency of
failing to effect appropriate fuel supply.
It will be clear from the foregoing that the swirl injection valve
A.sub.1 has distinctively excellent effects of atomization
characteristics and high response to the injection pressure which
cannot be attained by the fuel injection valve B and the swirl
injection valve C. In addition, the swirl chamber 8 and the
tangential pressurized fuel supply passages 40, which are the
essential elements of the swirl injection valve A.sub.1, can be
provided effectively in the nozzle member 4 and the side wall
portions of the pressurized fuel induction passages 42. Thus, the
swirl injection valve A.sub.1 is completely different from the
conventional injection valves in that high precision manufacturing
and machining can be effected simply by boring the tangential
pressurized fuel supply passages 40 through the wall of the nozzle
member 4 in communication with the pressurized fuel induction
passage 42 and the swirl chamber 8. Moreover, by fitting the plug
member 43 in the unnecessary open bores on the outer side of the
junctions of the tangential pressurized fuel supply passages 40 and
the pressurized fuel induction passages 42, pressurized fuel
induction passages of high precision can be easily and simply
formed to provide products of high quality with high production
efficiency. Particularly, the swirl injection valve A.sub.1 is
simplified in the shape and construction of the nozzle member 4,
with the resultant advantages that the manufacturing, machining and
assembling become easier to suit to mass production as compared to
conventional injection valves, and that the valve is free from
various troubles, has increased durability, is easy to handle and
can be produced at lower cost.
Moveover, the swirl injection valve A.sub.1 of the first
embodiment, when applied to the diesel engine 100, can effect the
supply of injection fuel in an optimum manner so that it becomes
possible to attain complete combustion of the fuel, prevent air
pollution due to the production of toxic gases, ensure stable and
smooth operation of the engine, and reduce the fuel
consumption.
The second embodiment of the present invention, swirl injection
valve A.sub.2, is of a type different from the above-described
first embodiment and will now be described. As shown in FIGS. 15 to
17, in the swirl-injection valve A.sub.2, a plunger is moved in
response to an energizing pulse voltage which is applied to an
electromagnetic coil, thereby seating and unseating the needle
valve to control the opening and closing of the pressurized fuel
induction passage, for controlling the amount of injected fuel,
according to the length of the conduction periods of the
electromagnetic coil. The electromagnetic or electronic swirl
injection valve A.sub.2 (or electronic fuel injector), has at the
fore end of a nozzle body 201 a nozzle member 204 of a pintle type
(including throttle type) nozzle, including a fuel injection port
202 and a conical valve seat 203 formed in an inner cavity of the
nozzle member 204 in communication with the injection port. The
nozzle body 201 and the nozzle member 204 are centrally provided
with a needle valve guide bore 205 and a guide bore 213 for
respectively slidably receiving a precision fitted needle valve 206
having a stopper 207, and a plunger 214 which is integrally
connected to the needle valve 206. The needle valve 206, received
in the nozzle member 204, forms a pintle type nozzle different from
the first embodiment and has a conically shaped fore end for
abutting engagement with the valve seat 203 in an airtight fashion.
The needle valve is further provided with a valve device 209 for
intermittently injecting fuel by the opening and closing operation
of the needle valve 206 with the valve seat 203 which is controlled
by energization and de-energization of the electromagnetic coil of
electromagnetic needle valve control device 250. Between the valve
seat 203 of the injection port 202 which is centrally located in
the nozzle member 204 and a conical pressure receiving surface 261
provided at the fore end of the needle valve 206, there is provided
a swirl chamber 208 which consists of a coaxial and connecting
combination of hollow truncated cone and cylindrical sections. The
swirl chamber 208 has about the same relation between its shape and
its dimension (diameter di, height h and diameter of the fuel
injection port de) as that of the first embodiment.
In the swirl injection valve A.sub.2 of the second embodiment, the
swirl chamber 208 is communicated with tangential pressurized fuel
supply passages 240 which are formed through the side wall of the
nozzle member 204. The nozzle member 204 has pressurized fuel
induction passages 242 formed through its side wall 241 parallel
with the axis of the swirl chamber 208, while the nozzle body 201
has a pressurized fuel induction passage 212 formed through its
side wall 211 coaxially with the swirl chamber 208. These
pressurized fuel induction passages 212 and 242 are communicable
with each other through a fuel supply passage 297 and an annular
groove or space 243' provided between the opposing end faces of the
nozzle member 204 and the nozzle body 201. The passage 297
communicates with passage 242 through its center bore 298 and side
openings 299, as seen in FIG. 15. At the lower end of valve A.sub.2
(FIG. 16), the pressurized fuel induction passage 242 communicates
with the fuel injection port 202 through the tangential pressurized
fuel supply passages 240, swirl chamber 208 and valve device 209.
At the upper end, the pressurized fuel induction passage 212
communicates with an externally provided fuel source (not shown)
through its fuel pump (not shown). A spring seat 262 is provided on
the plunger 214 for receiving one end of a valve spring 260 which
urges the needle valve 206 into abutting engagement with the valve
seat 203. The other end of valve spring 260 abuts one end of a
hollow chamber 263 which is fitted in and integrally secured to the
pressurized fuel induction passage 212. An annular electromagnetic
needle valve control device 250, which controls the seating and
unseating operation of the needle valve 206, is positioned within
the side wall of the nozzle body 201 and around the pressurized
fuel induction passage 212 in an airtight and insulated manner, as
shown in FIG. 15. The electromagnetic needle valve control device
250 has a fixed iron core 251 in which a member 212' is coaxially
fitted to form the pressurized fuel induction passage 212. An
electromagnetic coil 252 is wound a plural number of turns around
the outer periphery of the fixed core. A yoke 253 covers the
electromagnetic coil 252 and at the same time secures the fixed
iron core 251 in position. The outer wall member 201' of the nozzle
core 201 encases the fixed core 251, electromagnetic coil 252, yoke
253 and nozzle member 241 integrally therein in an airtight and
well-insulated manner. The fixed core 251 receives in its inner
cavity one end of the afore-mentioned plunger 214. When an
energizing pulse voltage is applied to the electromagnetic coil
252, the electromagnetic needle valve control device 250 produces
an electromagnetic attractive force, thereby attracting the plunger
214 upwardly to open the fuel passage between the needle valve 206
and the valve seat 203 for fuel injection. As soon as the
energizing pulse voltage to the electromagnetic coil 252 is cut
off, the electromagnetic attractive force ceases and the plunger
214 is urged to descend by the action of the valve spring 260 to
close the fuel passage between the needle valve 206 and the valve
seat 203, thereby cutting off the fuel injection. The
electromagnetic coil 252 is conductively connected to a connector
255 which, in turn, is connected to a computer (not shown) through
suitable wiring (not shown) to receive electric injection signals
which have been calculated by the computer, and amplified by a
power amplifier (not shown).
The swirl injection valve A.sub.2 of the second embodiment will now
be described when applied to a gasoline engine (spark ignition), as
shown in FIG. 17, in which those parts common to FIG. 14 are
designated by common reference numerals.
The gasoline engine 280 is of the type in which the fuel is
injected into the intake pipe. The intake system of the engine is
as follows. In the upstream portion of an intake passage 281, there
are provided (but not shown) an air filter and a throttle valve,
the latter being opened and closed to control the amount of intake
air. In the downstream portion of the intake passage, there are
provided a combustion chamber 283 receiving a sparking head 282 of
a spark plug SP, an intake port 284 communicable with the
combustion chamber, and an intake valve 285 which performs the
opening and closing control of the intake port. The swirl injection
valve A.sub.2 is air-tightly mounted in a mounting hole 287 which
is provided in the wall 286 (intake manifold) of the intake passage
281, upstream of the intake valve 285, to inject the fuel toward
the valve seat 288 of the intake valve 285.
The operational effects of the swirl injection valve A.sub.2 of the
second embodiment having the above-described arrangement will now
be explained.
In the intake stroke of the gasoline engine 280, a predetermined
amount of air is drawn into the combustion chamber 283 through the
intake passage 281, throttle valve, intake valve 285 and intake
port 284. At this moment, the swirl injection valve A.sub.2 sprays
the fuel toward the valve seat 288 with good atomization
characteritics and response to the injection pressure, and the
sprayed fuel efficiently and uniformly spreads into and mixes with
the intake air to form a combustible mixture of predetermined
air-fuel ratio. The air-fuel mixture taken into the combustion
chamber 283 is compressed in the succeeding compression stroke and
then ignited by the spark plug SP to effect and complete combustion
in an appropriate manner.
To explain the operation of the swirl injection valve A.sub.2 of
the second embodiment more particularly, when the energizing pulse
voltage to be supplied to the electromagnetic coil 252 is cut off
to eliminate its electromagnetic force, the plunger 214 is urged to
its lower position by the action of the valve spring 260, closing
the fuel passage between the needle valve 206 and the valve seat
203, namely, closing the injection port 202. However, as soon as
the energizing pulse voltage is applied to the electromagnetic coil
252 to produce electromagnetic attractice force, the plunger 214 is
magnetically lifted against the force of the valve spring 260,
opening the passage between the needle valve 206 and the valve seat
203, namely, opening the injection port 202. Simultaneously, the
fuel flows through the pressurized fuel induction passages 212, 242
and the pressurized fuel supply tangential passages 240 into the
swirl chamber 208, which has a small diameter and height similar to
the first embodiment. Then, the fuel is swirled by tangentially
supplying the pressurized fluid having no velocity component of an
axial direction to the swirl chamber, and sprayed into the intake
passage 281 in the form of a high velocity atomized spray with
optimum atomization characteristics and atomization response to the
injection pressure.
Following are examples of spray conditions which are obtained when
the swirl injection valve A.sub.2 of the second embodiment is
applied to the above-described gasoline engine 280.
Under the gasoline engine operating conditions where the fuel
pressure is 2 kg/cm.sup.2 and the engine speed is n=1500 rpm, the
spray produced by the swirl injection valve A.sub.2 at an initial
time point of injection immediately takes the form of a
trumpet-like liquid film, as shown in FIG. 18. The moment the
liquid film is spread, it becomes thinner and breaks up in the
periphery portions, forming a spray of fine particles. The valve
A.sub.2 has excellent atomization characteristics and response to
the injection pressure, attaining the same practical satisfactory
effects as the swirl injection valve A.sub.1 of the first
embodiment.
In continued injection, the swirl injection valve A.sub.2 produces
a spray of liquid film, the shape of which is more diverged than
the trumpet shape, as shown in FIG. 19. The spread liquid film
becomes thinner, and immediately and uniformly atomizes over a
large area to form a spray of atomized fuel which easily diffuses
and mixes with air, giving substantially the same effects as those
of swirl injection valve A.sub.1 of the first embodiment.
Upon completion of fuel injection, the swirl injection valve
A.sub.2 immediately cuts off the spray supply as shown in FIG. 20,
ensuring the optimum atomization characteristics such that the
sprayed fuel may retain the uniformly atomized state until the last
time point and giving substantially the same effects as the swirl
injection valve A.sub.1 of the first embodiment.
The superiority of the spray conditions attained by the swirl
injection valve A.sub.2 of the second embodiment will be obvious
upon comparing them with the spray conditions of the conventional
electromagnetic fuel injection valve B which has a pintle nozzle 69
in the nozzle member 49, as shown in FIG. 8.
More particularly, when the fuel injection valve B is applied to
the gasoline engine 280 under the same fuel pressure and same
engine speed as that of the second embodiment, at the initial time
point of injection, the injected fuel takes the form of a rod-like
liquid film, as shown in FIG. 21, without spreading and in the
distant portions from the injection port, the injected fuel spreads
to form an assembly of extremely coarse particles where the flow
rate of fuel is non-uniform and there are no atomized particles,
showing defective atomization characteristic, low response to the
injection pressure, and dripping of the fuel.
In the continued fuel injection by the fuel injector valve B, the
fuel is injected in the form of a liquid film with a relatively
small injecting angle, as shown in FIG. 22. The liquid film becomes
thinner as soon as it is spread and becomes an assembly of very
coarse particles and liquid films in the distant portions from the
injection port, thereby failing to attain good atomization even at
this time point. It is difficult in practice to obtain the
excellent atomization characteristics and high response to the
injection pressure attained by the swirl injection valve A.sub.2 of
the second embodiment.
Further, at the time point immediately before the completion of
injection by the fuel injector valve B, the fuel is injected in the
form of an assembly of very coarse particles and the liquid film,
as shown in FIG. 23, fails to completely stop the injection at the
final point, resulting in cut-off failures and after-dribbling of
the fuel.
It will be seen from the foregoing description that the swirl
injection valve A.sub.2 of the second embodiment realizes
distinctly improved atomization characteristics and response to the
injection pressure which cannot be achieved by the fuel injection
valve B or swirl injection valve C. In addition, the swirl
injection valve A.sub.2 of the second embodiment has a great
advantage in that it is simplified in shape and construction, and
extremely easy to manufacture, machine and assemble to suit mass
production, as compared with conventional counterparts. It further
has practical advantages because it is free from various troubles,
excellent in durability and reliability, easy to handle and low in
cost.
Moreover, when swirl injection valve A.sub.2 of the second
embodiment is applied to the intake pipe injection type gasoline
engine 280 (spark ignition engine), the fuel can be supplied in an
optimum manner as described hereinbefore so that it becomes
possible to effect complete combustion, suppress generation of
toxic gases, prevent air pollution by exhaust gases, stabilize and
smoothen the operation of the engine, improve various operational
efficiencies of the engine considerably, and reduce the fuel cost
to a significant degree.
The swirl injection valve A.sub.3 forming the third embodiment of
the invention is shown in FIGS. 24 to 26 and is suited to a start
injector. The shape and construction of the electromagnetic needle
valve control device are the same as those of the second
embodiment. Also, the shape and construction of the nozzle member
and the needle valve, are the same as those of the first embodiment
so that common component parts are designated by common reference
numerals.
The swirl injection valve A.sub.3 of the third embodiment is
different from the foregoing embodiments mainly in those points
which will be mentioned in the following description. Upon
application of the energizing pulse voltage to the electromagnetic
coil 252, the needle valve control device 250 generates an
electromagnetic attracting force to pull the plunger 214 upwardly
against the action of the valve spring 260, thereby opening the
fuel passage between the needle valve 6 and valve seat 3 of the
valve device 9 for injecting, through the injection port 2, the
fuel which is supplied through the pressurized fuel induction
passages 212, 242, tangential pressurized fuel supply passage 40,
and swirl chamber 8 to form a strong and fast swirl flow
therewithin. As soon as the energizing pulse voltage is cut off,
the electromagnetic attractive force of the needle valve control
device 250 ceases and the plunger 214 is urged downwardly by the
spring force of the valve spring 260 to close the passage between
the needle valve 6 and valve seat 3, cutting off the injection and
supply of the fuel.
FIG. 26 shows the swirl injection valve A.sub.3 of the third
embodiment as applied to a cold start injector of a gasoline engine
(spark ignition engine). The swirl injection valve A.sub.3 is
air-tightly mounted at the center of the top wall of a surge tank
383 disposed between a throttle valve 381 in the intake passage 281
and the intake pipe 382 for the purpose of improving the starting
performance under cold temperature conditions. The injection valve
A.sub.3 has its injection port 2 facing the interior of the surge
tank 383.
The swirl injection valve A.sub.3 of the third embodiment operates
in the following manner. The swirl injection valve A.sub.3 is
operated by a thermo-time switch (not shown) in the engine which
operates only under conditions when the engine cooling water
temperature is below approximately 35.degree. C. to inject fuel
with optimum atomization characteristics and high atomizing
response to the injection pressure. Once the engine is started, the
thermo-time switch is de-energized to immediately stop the fuel
injection by the swirl injection valve A.sub.3, cutting off the
fuel immediately without after-dribbling. The cold start injector
of this type requires the fuel to be supplied in optimumly atomized
conditions in order to improve the starting performance of the
engine when the engine cooling water temperature is low. The swirl
injection valve A.sub.3 of the third embodiment is particularly
suitable for a start injector and superior to the conventional
counterparts in fuel atomizing characteristics and in the atomizing
response to the injection pressure.
Following are explanations of conditions of the sprays of fuel
injected by the swirl injection valve A.sub.3 of the third
embodiment which have been applied as a start injector of the
aforementioned gasoline engine 280.
At an initial time point of fuel injection by the swirl injection
valve A.sub.3, the fuel is injected immediately in the form of a
trumpet-shaped liquid film. The liquid film becomes thinner as it
is spread and breaks up in the peripheral portions into a multitude
of atomized particles, showing optimum atomization characteristics
and high atomizing response to the injection pressure from the
initial point of injection. Hence, the swirl injection valve
A.sub.3 of the third embodiment has great utility as a start
injector since its use effectively precludes coarse fuel particles
which appear due to fuel stagnation in the spray (FIG. 27) at the
initial time point of injection by conventional swirl injection
valves used as a start injector (not shown). In addition, almost
the same effects to the foregoing embodiments can be achieved.
In the continued injection by the swirl injection valve A.sub.3,
the fuel is injected in the form of a liquid film of trumpet shape
as shown in FIG. 28, and as soon as it spreads, the liquid film
becomes thinner and is uniformly atomized over a large area to
produce a spray of atomized fuel which diffuses with air in the
same manner as in the foregoing embodiments.
At a time point immediately before termination of injection by the
swirl injection valve A.sub.3, the fuel is injected in the form of
a liquid film of tulip shape, as shown in FIG. 29. The injected
fuel becomes thinner in the distant portions and maintains an
uniformly atomized state, showing the optimum atomization
characteristics until the termination of injection, when the fuel
injection is cut off in the same manner as in the foregoing
embodiments.
It will be seen from the foregoing description that the swirl
injection valve A.sub.3 of the third embodiment is particularly
useful as a start injector and can contribute to improve the
starting operation of the engine and to maintain its stable, smooth
and efficient operation. By use of the swirl injection valve
A.sub.3, practical effects are obtained which could not have been
attained by the conventional valves. In other respects, the swirl
injection valve A.sub.3 of the third embodiment has the same
effects as the foregoing embodiments.
The swirl injection valve A.sub.4, which appears in FIG. 30 and
constitutes the fourth embodiment of the present invention, differs
from the foregoing embodiments mainly in that a swirl chamber 508
is formed in the wall of a nozzle member 504 and at a position
downstream of a valve device 509. In other respects, it has the
same construction as the foregoing embodiments. The following
description is focused mainly on the different points, in which
common parts are designated by common reference numerals and their
explanations are omitted.
The nozzle member 504 has a bottomed swirl chamber 508 bored
coaxially into the center of its fore end. The swirl chamber 508 is
in communication with tangential pressurized fuel supply passages
40 which are formed through the side wall of the nozzle member 504
in a direction tangential to the inner periphery of the swirl
chamber 508. These tangential pressurized fuel supply passages are
in communication with pressurized fuel induction passages 42a which
are formed through the bottom wall of the nozzle member 504 in
parallel relation with the central axis of the bore of the needle
valve chamber 5, needle valve 6, nozzle member 504 and swirl
chamber 508. Plug members 43 are hermetically and integrally fitted
into bore portions which are located on the outer sides of
junctions of the tangential fuel supply passages 40 and the fuel
induction passages 42a. A box nut 44 is coaxially and integrally
fixed to the outer periphery of the fore or lower end of the nozzle
member 504 by a threaded portion 45. The box nut 44 has an
injection port 502 on its axis in coaxial relation with the bore of
the needle member 504. The above-mentioned pressurized fuel
induction passage 52a opens between a conically shaped apex end 561
of the needle valve 6, located forward of its conical pressure
receiving surface 61, and a conical valve seat 562. A fuel sink 563
is bored in the wall of the nozzle member 504 between the conical
pressure receiving surface 61 of the apex end 561 of the needle
valve 6, in communication with the pressurized fuel induction
passages 42. In the swirl injection valve A.sub.4 of the fourth
embodiment, the apex end 561 of the needle valve 6 is constantly
urged to seat on the valve seat 562 by the action of the valve
spring, where it blocks communication between the fuel sink 536 and
the fuel induction passages 42a and cuts off the fuel supply. The
passage between the apex end 561 of the needle valve 6 and the
valve seat 562 is opened when the needle valve 6 is lifted against
the action of the valve spring, communicating the fuel sink 563
with the fuel induction passages 42a to supply the fuel through the
tangential passages 40 and swirl chamber 508 and spray it outwardly
through the injection port 502.
FIGS. 31 and 32 illustrate the swirl injection valve A.sub.4 of the
fourth embodiment as applied to a gasoline engine 581 with an
auxiliary combustion chamber.
The main combustion chamber 518 receives through the intake valve
109 a lean air-fuel mixture consisting of the air which is taken in
through the intake passage 105 and the sprayed fuel from the swirl
injection valve A.sub.2. The main combustion chamber 518
communicates with the auxiliary combustion chamber 520 through an
intercommunicating bore 510 which is formed tangentially to
generate vortical flows. The swirl injection valve A.sub.4 is
mounted with its injection port 502 disposed within the auxiliary
combustion chamber 520 to inject a predetermined amount of fuel
into the auxiliary combustion chamber 520 with a predetermined
timing in synchronism with the engine operation, and supply a rich
air-fuel mixture to the auxiliary combustion chamber 520 which has
already been supplied with a lean air-fuel mixture. A spark plug SP
is also provided in the auxiliary combustion chamber 520 with its
sparking portion 282 disposed at a predetermined distance from the
swirl injection valve A.sub.4.
In this arrangement, the swirl injection valve A.sub.4 of the
fourth embodiment and the pre-chamber type gasoline engine 581
operate in the following manner.
In the intake stroke, the gasoline engine 581 is supplied with a
lean air-fuel mixture in the main combustion chamber 518, whereas a
rich air-fuel mixture is formed in the auxiliary combustion chamber
520. Then, the rich air-fuel mixture in the auxiliary combustion
chamber 520 is ignited by the spark plug SP and burned therein, the
flames of which propagate into the main combustion chamber 518 to
ignite and burn the lean air-fuel mixture to complete stratified
combustion appropriately.
In addition to the excellent atomization characteristics and
response to the injection pressure attained in the preceding
embodiments due to the formation of a strong and fast swirl flow
within the swirl chamber 508, the swirl injection valve A.sub.4 of
the fourth embodiment also has an advantage in that it is simple in
construction to facilitate its manufacturing, machining and
assembling processes, coupled with its practical merits such as
trouble-free durability, reliability and easy handling.
Furthermore, the swirl injection valve A.sub.4 applied to the
pre-chamber type gasoline engine 581 serves to effect efficiency
stratified combustion, preventing the generation of toxic cases,
stabilizing and smoothening the engine operation, enhancing the
efficiencies of various operations, and reducing the fuel cost.
In summary, the swirl injection valve according to the present
invention comprises an injection port provided at the fore end of a
nozzle body for injecting a pressurized fluid to be supplied, a
pressurized fluid induction passage provided in the wall of said
nozzle body in communication with said injection port and a
pressurized fluid supply source, a valve device mounted in said
pressurized fluid induction passage to control the fluid injection
by on-off controlling the fuel supply to said injection port, a
swirl chamber provided in the wall of said nozzle body at a
position proximal to and in communication with said injection port,
and tangential pressurized fuel supply passages, each of which has
one end which communicates with a corresponding one of said
pressurized fluid induction passages and the other end which opens
into said swirl chamber in a direction tangential to the inner
periphery thereof to impart swirling movement about the axis of
said swirl chamber to the pressurized fluid to be supplied thereto,
said pressurized fluid being injected with a predetermined
timing.
The above-described swirl injection valve of the present invention
has a remarkably improved construction. Particularly, the swirl
injection valve differs from the conventional counterparts in that
it has the pressurized fluid induction passage, for example, the
tangential pressurized fluid supply passage bored from outside
through the wall of the nozzle body in communication with the swirl
chamber and the pressurized fluid induction passage, allowing the
manufacture and machining of the nozzle member efficiently and with
high precision. In addition, a pressurized fluid induction passage
of high precision can be formed by fitting a plug member in the
unnecessary bore portions on the outer side of the junction of the
tangential pressurized fluid supply passage and the pressurized
fluid induction passage, making it possible to improve the quality
of the products with high working efficiency and in a simplified
manner. Therefore, there can be provided a swirl injection valve of
a simplified construction through extremely facilitated
manufacturing, machining and assembling processes, suitable for
mass production, while assuring excellent durability, reliability
and ease of handling of the valve at a reduced cost. Furthermore,
the valve of the present invention forms a strong and fast swirl
flow within the swirl chamber by tangentially supplying the
pressurized fluid having no velocity component of an axial
direction into the swirl chamber, so that the valve has the
practical effect of spraying the pressurized fluid with optimum
atomization characteristics and high response to the injection
pressure. Therefore, it is capable of various applications in
diversified industrial fields. For instance, it can be applied to
an internal combustion engine to effect appropriate fuel supply for
complete combustion of the fuel while preventing generation of
toxic gases which cause air pollution, stabilizing and smoothening
the engine operation, improving the efficiency of various
operations by the engine, and reducing the fuel cost.
The swirl injection valve according to the present invention is not
limited to the particular embodiments illustrated in the foregoing
description and allows various modifications and alterations as
shown below, where those parts common to the foregoing embodiments
are designated by common reference numerals.
For example, the swirl injection valve A.sub.5 with the nozzle
member 4 shown in FIG. 33 may have the swirl chamber 8 constructed
such that when the needle valve 6 is seated on the valve seat 3 by
the action of the valve spring or other biasing force, it is
completely occupied by the needle valve 6, to block the
communication between the injection port 2 and the tangential fuel
supply passages 40 by the conical fore end of the needle valve 6.
The swirl chamber 8 is formed in a hollow conical shape defined by
the outer wall portions of the conical fore end of the needle valve
6 and the inner peripheral wall of the valve seat 3 when the needle
valve 6 is lifted against the action of the valve spring or other
valve biasing force. In this instance, the fuel is supplied to the
swirl chamber 8 through the pressurized fuel induction passages 42
and the tangential fuel supply passages 40, and injected outwardly
through the injection port 2, with optimum atomization
characteristics and quick response to the injection pressure in a
manner similar to the above-described embodiments.
Further, the swirl injection valve A.sub.6 with the nozzle member
4' shown in FIG. 34 may be constructed such that a substantially
cylindrical swirl chamber 8' is provided in the wall of the nozzle
member 4' at a position located above the conical pressure
receiving surface 61 of the needle valve 6. The tangential
pressurized fuel supply passages 40 which tangentially open into
the swirl chamber 8' may not necessarily be provided in one and the
same plane as in the foregoing embodiments and may be provided in
different planes. For instance, as shown in FIG. 34, the tangential
fuel supply passages 40' may be disposed to tangentially open into
the swirl chamber 8' through its upper wall portion, with the axis
of each passage inclined with respect to the axis of the coaxially
mounted nozzle member 4' and needle valve 6, to thereby increase
the efficiency of fuel supply to the swirl chamber 8' and to
accelerate the swirling flows within the swirl chamber 8'. The
swirl injection valve A.sub.6 of this construction has the same
effects as the foregoing embodiments.
In addition to the foregoing embodiment, the swirl injection valve
of the present invention may be operated by mechanical actuation or
a pressure accumulating chamber to attain the same operations and
effects as in the preceding embodiments. The swirl injection valve
of the invention is applicable not only to the internal combustion
engines of the foregoing embodiments but also to the diesel or
gasoline engines of the type which requires injection of fuel into
a combustion chamber which is formed in the piston head or the
engines which use both a carburetor and a fuel injection
nozzle.
Moreover, the swirl injection valve of the present invention is not
limited to the values given in the foregoing embodiments with
respect to the diameter and height of the swirl chamber and the
diameter of the injection port, and may employ other
dimensions.
Furthermore, it may be mentioned that the swirl injection valve of
the invention may be provided with at least one pressurized fluid
induction passage and at least one tangential pressurized fluid
supply passage leading to the swirl chamber, in addition to those
shown in the preceding embodiments.
It should be understood that the present invention is not limited
to the embodiments which have the tangential pressurized fluid
supply passages bored through the wall of the nozzle body into
communication with the swirl chamber and the pressurized fluid
induction passages, but may be embodied in the form which has other
pressurized fluid induction passages bored in a similar manner
alone or in combination with the tangential fluid supply passages.
Similarly, the plug member may be used not only for closing the
tangential fluid supply passage but for closing unnecessary bore
portions of other fluid induction passages.
* * * * *